Wow. This is on ThinkGeek.com??

A classic yet modern watch. Besides the separate and unconventional seconds, hours and minute hands, the middle dial of the watch (which appears black in the photo) actually conceals a regular, clean, hour dot-markers dial.

As the second hand rotates, it turns a top, clear plastic piece that's polarized (like your sunglasses). This makes the dial fade from crystal clear, to a darker, darker, twilight shade (hence the name) until it is night-black. Then, 20 seconds (and rotations later) it goes in reverse - from complete darkness to perfect clarity. This goes on and on, dark to light, light to dark. It's jewelry in motion.

While how it works might be geeky, it's a modern and surprisingly cool looking watch. The leather band has no visible lugs, so it meets the watch case seamlessly, like a bracelet. The case is made with a sleek, matte aluminum finish. All the marker hands are different shapes. And it's an understated 36 mm in size, letting the watch itself shine without shouting.

To truly appreciate the watch in motion, watch the video on their site. $120.

UPDATE: Figures this isn't a ThinkGeek exclusive. It's from the Projects Watch Co., by designer Daniel Will-Harris - maker of the also modern and cool 'Reveal' Watch, among others. Check out the included pics for close ups of each phase.

Great Watch. It seems that it changes from light to dark every few seconds. Good looking...